Pelletized polyolefin

Ionomers are generally shipped in pellet form in the standard containers developed for large-volume polyolefins, eg, 500-kg boxes. Water-resistant liners are used to keep the products dry during shipment and storage. 

Polyolefins (Polyethylene, Polypropylene) Powder, pellets Tough and chemical resistant. Weak in creep and thermal resistance. Polyethylene maximum use temperature 210 F, polypropylene 260 F. May be injection and extrusion molded, vacuum formed. Low cost. Antistatic sheet and tiles, heat-shrinkable tubing, deicer boots. 

The origin of defects causing discoloration in polyolefin pellets can be identified using light and electron microscopy. For example, PE pellets from an in-plant recycle re-pelletlzing process contained pellets that were off color and had black specks, as shown In Fig. 11.6(a). One of these defects was isolated using the cross sectioning technique, as shown in Fig. 11.6(b). The cross section revealed an intense reddish particle that caused the discoloration of the pellet. 

Figure 11.7 EDX microanalysis of an inclusion in a polyolefin pellet cross section of Fig. 11.6(b). The analysis indicated that the particle was likely iron oxide...

Irradiation of polyolefins, particularly the family of polyethylenes, represents an important segment of the radiation processing. Polyolefins can be irradiated in many forms, such as pellets and powders, films, extruded and molded parts or as wire and cable insulation. 

PVC), polystyrene, ABS polymers, and polyurethanes. In tonnage terms, the largest application is in polyolefins. Pelletized black is usually employed. 

Typical applications for products and processes with high and low torque requirement are shown in Fig. 14.9. Typical uses of high torques are reinforcing and alloying of engineering plastics and compounding and pelletizing of polyolefin powders into polyolefin pellets, or direct extrusion of films. Low torques are used for products that are shear-sensitive or difficult to feed, such as those often found in the chemical/food/pharmaceutical industries. 

Liquid colors are compatible with a wide variety of polymers, including PVC, polyethylene vinyl acetate (EVA), nylons, PET, polycarbonate, alloys, high-temperature polymers, and the full range of polyolefins and styrenics. Many liquid colors are suitable to color food-contact polymers and comply with all government regulations worldwide for shipping, use, and disposal. Lead times for liquid color are typically less than those for pellet or other melted color concentrates, since the processing is quick and efficient. 

This is often conducted to make impact-resistant polyolefin blends. For this purpose, isotactic polypropylene, which is tough but somewhat brittle, is produced on the catalyst pellet in a first reaction step, using highly active stereospecific... 

U.S. Pat. No. 6,632,863 [115] (by Crane Plastics Company, Timber-Tech) discloses a wood-plastic composition manufactured as feedstock pellets comprising 55-90% cellulosic material such as wood flour and wood fiber, 10-40% of polyolefin such as HDPE, LDPE, and polypropylene, and 0-35% total of additive(s), such as lubricants and inorganic fillers, such as talc and mica. 

Cellulose-polyolefin composite pellets, 89 Cellulosic reinforced plastic composite, 89 Center point load, or concentrated load (3-pt load), 244, 252, 264 CertainTeed Corporation, 58, 79, 90 Cesa-mix 8468, 174 Cesa-mix 8611, 174 Chain breaking antioxidants, 526 Chain reaction, 526 Charpy impact resistance, 73 Chemark UV-234, 535 Chemark UV-326, 535 Chemical composition of fillers, 125, 133-154... 

Gech M. Saxena PR. Boosting properties and performance of polyolefin compounds with silicone pellets. International Polyolefins 2007, conference proceedings. Society of Plastics Engineers 2007. 

The production of polyolefins started in the research laboratories. Polyethylene was the first produced polyolefin in 1933 in the research laboratories of Imperial Chemical Company by E.W. Fawcett and R.O. Gibson, from pure ethylene by high pressure and temperature, polyethylene pellets are shown in Fig. 1.1. The production of PE is expected to reach 100 million of metric tons in 2018, and the investment of the production can reach 1 bn for new plants. 

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